GEVS_GSFC-STD-7000 Foarte Tare Carte

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GSFC-STD-7000

April 2005

Supersedes

GEVS-SE dated June, 1996

GENERAL ENVIRONMENTAL VERIFICATION STANDARD (GEVS)

For GSFC Flight Programs and Projects

Approved By:

Original signed by______________________________

Abigail Harper (Acting)

Director of Systems Safety and Mission Assurance

Original signed by

______________________________

Michael Ryschkewitsch

Director of Applied Engineering and Technology

Original signed by

______________________________

Arthur Obenschain

Director of Flight Programs and Projects

Original signed by

______________________________

Richard Day

Director of Mission Success

NASA GODDARD SPACE FLIGHT CENTER

Greenbelt, Maryland 20771


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ii

GEVS

Changes* to

GENERAL ENVIRONMENTAL VERIFICATION STANDARD

Change No. Date Nature of Change Initials

* This document is controlled by the GSFC Office of Mission Success


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TABLE OF CONTENTS

Paragraph Page

SECTION 1 -- GENERAL INFORMATION

1.1 PURPOSE.............................................................................................................................1-11.2 APPLICABILITY AND LIMITATIONS....................................................................................1-1

1.3 THE GSFC VERIFICATION APPROACH ............................................................................1-1

1.4 OTHER ASSURANCE REQUIREMENTS............................................................................1-2

1.5 RESPONSIBILITY FOR ADMINISTRATION........................................................................1-2

1.6 GEVS CONFIGURATION CONTROL AND DISTRIBUTION...............................................1-2

1.7 APPLICABLE DOCUMENTS................................................................................................1-3

1.7.1 Safety Requirements.............................................................................................................1-3

1.7.2 NSTS Interface Requirements ..............................................................................................1-3

1.7.3 ELV Payload User Manuals ..................................................................................................1-3

1.7.4 Fracture Control and Stress Corrosion .................................................................................1-3

1.7.5 Spacecraft Tracking and Data Network Simulation ..............................................................1-3

1.7.6 Deep Space Network (DSN) Simulation ...............................................................................1-3

1.7.7 NASA Standards ...................................................................................................................1-31.7.8 Military Standards for EMC Testing ......................................................................................1-4

1.7.9 Military Standards for Non-Destructive Evaluation ...............................................................1-4

1.8 DEFINITIONS........................................................................................................................ 1-4

1-9 CRITERIA FOR UNSATISFACTORY PERFORMANCE......................................................1-9

1.9.1 Failure Occurrence................................................................................................................1-9

1.9.2 Failures with Retroactive Effect............................................................................................. 1-9

1.9.3 Failure Reporting................................................................................................................... 1-9

1.9.4 Wear Out ...............................................................................................................................1-9

1.10 TEST SAFETY RESPONSIBILITIES....................................................................................1-9

1.10.1 Operations Hazard Analysis, Responsibilities For................................................................1-9

1.10.2 Treatment of Hazards .........................................................................................................1-10

1.10.3 Facility Safety......................................................................................................................1-10

1.10.4 Safety Responsibilities During Test ....................................................................................1-10

1.11 TESTING OF SPARE HARDWARE ...................................................................................1-10

1.12 TEST FACILITIES, CALIBRATION.....................................................................................1-11

1.13 TEST CONDITION TOLERANCES....................................................................................1-11

SECTION 2 -- VERIFICATION PROGRAM

SECTION 2.1 - SYSTEM PERFORMANCE VERIFICATION

2.1 SYSTEM PERFORMANCE VERIFICATION.....................................................................2.1-1

2.1.1 Documentation Requirements ...........................................................................................2.1-12.1.1.1 System Performance Verification Plan ..............................................................................2.1-1

2.1.1.1.1 Environmental Verification Plan .........................................................................................2.1-1

2.1.1.2 System Performance Verification Matrix............................................................................2.1-2

2.1.1.2.1 Environmental Test Matrix .................................................................................................2.1-2

2.1.1.3 Environmental Verification Specification............................................................................2.1-3

2.1.1.4 Performance Verification Procedures ................................................................................2.1-3

2.1.1.5 Verification Reports............................................................................................................2.1-3

2.1.1.6 System Performance Verification Report...........................................................................2.1-4

2.1.1.7 Instrument Verification Documentation..............................................................................2.1-4


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SECTION 2.2 - ENVIRONMENTAL VERIFICATION

2.2 APPLICABILITY .................................................................................................................2.2-1

2.2.1 Test Sequence and Level of Assembly..............................................................................2.2-1

2.2.2 Verification Program Tailoring............................................................................................2.2-1

2.2.2 Test Factors/Durations.......................................................................................................2.2-32.2.3 Qualification if Hardware by Similarity ...............................................................................2.2-3

2.2.4 Test Factors/Durations.......................................................................................................2.2-4

2.2.5 Structural Analysis/Design Factors of Safety.....................................................................2.2-4

SECTION 2.3 - ELECTRICAL FUNCTION & PERFORMANCE

2.3 ELECTRICAL FUNCTION TEST REQUIREMENTS.........................................................2.3-1

2.3.1 Electrical Interface Tests....................................................................................................2.3-1

2.3.2 Comprehensive Performance Tests ..................................................................................2.3-1

2.3.3 Limited Performance Tests ................................................................................................2.3-1

2.3.4 Performance Operating Time and Failure-Free Performance Testing ............................. .2.3-2

2.3.5 Limited-Life Electrical Elements.........................................................................................2.3-2

SECTION 2.4 - STRUCTURAL AND MECHANICAL

2.4 STRUCTURAL AND MECHANICAL VERIFICATION REQUIREMENTS.........................2.4-1

2.4.1 Structural Loads Qualification............................................................................................2.4-1

2.4.1.1 Coupled Loads Analysis.....................................................................................................2.4-5

2.4.1.1.1 Analysis-Strength Qualification..........................................................................................2.4-5

2.4.1.1.2 Analysis-Clearance Verification .........................................................................................2.4-6

2.4.1.2 Modal Survey .....................................................................................................................2.4-7

2.4.1.3 Design Strength Qualification ............................................................................................2.4-8

2.4.1.3.1 Strength Qualification - Beryllium.......................................................................................2.4-9

2.4.1.4 Structural Reliability (Residual Strength Qualification) ....................................................2.4-10

2.4.1.4.1 Primary and Secondary Structure....................................................................................2.4-10

2.4.1.5 Acceptance Requirements...............................................................................................2.4-12

2.4.2 Vibroacoustic Qualification...............................................................................................2.4-13

2.4.2.1 Fatigue Life Considerations .............................................................................................2.4-14

2.4.2.2 Payload Acoustic Test......................................................................................................2.4-14

2.4.2.3 Payload Random Vibration Tests ....................................................................................2.4-15

2.4.2.4 Subsystem/Instrument Vibroacoutic Tests.......................................................................2.4-16

2.4.2.5 Component/Unit Vibroacoustic Tests...............................................................................2.4-16


2.4.2.7 Retest of Reflight Hardware.............................................................................................2.4-20

2.4.2.8 Retest of Reworked Hardware.........................................................................................2.4-20

2.4.3 Sinusoidal Sweep Vibration Qualification ........................................................................2.4-20

2.4.3.1 ELV Payload Sine Sweep Vibration Tests.......................................................................2.4-21

2.4.3.2 ELV Payload Subsystem (including Instruments) and Component Sine Sweep

Vibration Tests .................................................................................................................2.4-22


2.4.4 Mechanical Shock Qualification.......................................................................................2.4-24


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2.4.4.1 Subsystem Mechanical Shock Tests ...............................................................................2.4-24

2.4.4.2 Payload (Spacecraft) Mechanical Shock Tests ...............................................................2.4-26


2.4.5 Mechanical Function Verification .....................................................................................2.4-27

2.4.5.1 Life Testing.......................................................................................................................2.4-27

2.4.5.2 Demonstration..................................................................................................................2.4-302.4.5.3 Torque/Force Margin........................................................................................................2.4-34


2.4.6 Pressure Profile Qualification...........................................................................................2.4-36

2.4.6.1 Demonstration..................................................................................................................2.4-36


2.4.7 Mass Properties Verification ............................................................................................2.4-37

2.4.7.1 Demonstration..................................................................................................................2.4-37


SECTION 2.5 - EMC

2.5 ELECTROMAGNETIC COMPATIBILITY (EMC) REQUIREMENTS.................................2.5-1

2.5.1 Requirements Summary ....................................................................................................2.5-1

2.5.1.1 The Range of Requirements..............................................................................................2.5-1

2.5.1.2 Testing at Lower Levels of Assembly ................................................................................2.5-3

2.5.1.3 Basis of the Tests...............................................................................................................2.5-3

2.5.1.4 Safety and Controls............................................................................................................2.5-4

2.5.2 Emission Requirements .....................................................................................................2.5-4

2.5.2.1 Conducted Emission Limits................................................................................................2.5-4

2.5.2.2 Radiated Emission Limits...................................................................................................2.5-5

2.5.2.3 Acceptance Requirements.................................................................................................2.5-7

2.5.3 Susceptibility Requirements...............................................................................................2.5-7

2.5.3.1 Conducted Susceptibility Requirements ............................................................................2.5-7

2.5.3.2 Radiated Susceptibility Requirements ...............................................................................2.5-9


2.5.4 Magnetic Properties .........................................................................................................2.5-12

2.5.4.1 Initial Perm Test ...............................................................................................................2.5-12

2.5.4.2 Perm Levels After Exposures to Magnetic Field..............................................................2.5-12

2.5.4.3 Perm Levels After Exposures to Deperm Test.................................................................2.5-12

2.5.4.4 Induced Magnetic Field Measurements...........................................................................2.5-12

2.5.4.5 Stray Magnetic Field Measurements ...............................................................................2.5-12

2.5.4.6 Subsystem Requirements................................................................................................2.5-12

2.5.4.7 Acceptance Requirements...............................................................................................2.5-122.5.4.8 Notes on Magnetics Terminology and Units Used in GEVS............................................2.5-13

SECTION 2.6 - THERMAL

2.6 VACUUM, THERMAL, AND HUMIDITY VERIFICATION REQUIREMENTS....................2.6-1

2.6.1 Summary of Requirements ................................................................................................2.6-1

2.6.2 Thermal-Vacuum Qualification...........................................................................................2.6-1

2.6.2.1 Applicability ........................................................................................................................2.6-4


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2.6.2.2 Special Considerations ......................................................................................................2.6-4

2.6.2.3 Level of Testing..................................................................................................................2.6-6

2.6.2.4 Test Parameters.................................................................................................................2.6-6

2.6.2.5 Test Setup........................................................................................................................2.6-10

2.6.2.6 Demonstration..................................................................................................................2.6-10

2.6.2.7 Special Tests....................................................................................................................2.6-11

2.6.2.8 Failure-Free-Performance................................................................................................2.6-12

2.6.3 Thermal Balance Qualifications .......................................................................................2.6-12

2.6.3.1 Alternative Methods .........................................................................................................2.6-13

2.6.3.2 Use of a Thermal Analytical Model ..................................................................................2.6-13

2.6.3.3 Method of Thermal Simulation.........................................................................................2.6-13

2.6.3.4 Internal Power ..................................................................................................................2.6-16

2.6.3.5 Special Considerations ....................................................................................................2.6-16

2.6.3.6 Demonstration..................................................................................................................2.6-16


2.6.4 Temperature-Humidity Verification ..................................................................................2.6-17

2.6.4.1 Temperature-Humidity Verification: Manned Spaces ......................................................2.6-17

2.6.4.1.1 Applicability ......................................................................................................................2.6-172.6.4.1.2 Demonstration..................................................................................................................2.6-17

2.6.4.2 Temperature-Humidity Verification: Descent and Landing ..............................................2.6-17

2.6.4.2.1 Special Considerations ....................................................................................................2.6-17

2.6.4.2.2 Demonstration..................................................................................................................2.6-17

2.6.4.2.3 Acceptance Requirements...............................................................................................2.6-17

2.6.4.3 Temperature-Humidity: Transportation and Storage .......................................................2.6-18

2.6.4.3.1 Applicability ......................................................................................................................2.6-18

2.6.4.3.2 Demonstration..................................................................................................................2.6-18

2.6.4.3.3 Acceptance Requirements...............................................................................................2.6-18

2.6.5 Leakage (Integrity Verification) ........................................................................................2.6-18

2.6.5.1 Levels of Assembly ..........................................................................................................2.6-18

2.6.5.2 Demonstration..................................................................................................................2.6-18


SECTION 2.7 - CONTAMINATION CONTROL

2.7 CONTAMINATION CONTROL PROGRAM....................................................................... 2.7-1

2.7.1 Applicability ........................................................................................................................2.7-1

2.7.2 Summary of Verification Process.......................................................................................2.7-1

2.7.3 Contamination Sensitivity...................................................................................................2.7-1

2.7.4 Contamination Allowance...................................................................................................2.7-2

2.7.5 Contamination Budget........................................................................................................2.7-2

2.7.6 Contamination Control Plan ...............................................................................................2.7-2

2.7.7 Other Considerations .........................................................................................................2.7-2

SECTION 2.8 - END-TO-END TESTING

2.8 END-TO-END COMPATIBILITY TESTS AND SIMULATIONS .........................................2.8-1

2.8.1 Compatibility Tests.............................................................................................................2.8-1

2.8.2 Mission Simulations ...........................................................................................................2.8-1


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Appendix A

General Information ...................................................................................................A-1 - A-14

Tables

Table

2.2-1 Flight System Hardware Levels of Assembly.....................................................................2.2-3

2.2-2 Test Factors/Durations.......................................................................................................2.2-5

2.2-3 Flight Hardware Design/Analysis Factors of Safety Applied to Limit Loads..................... .2.2-6

2.4-1 Structural and Mechanical Verification Test Requirements...............................................2.4-2

2.4-2 Minimum Probability-Level Requirements for Flight Limit (maximum expected) Level .....2.4-3

2.4-3 Generalized Random Vibration Test Levels, Components.(STS or ELV) .......................2.4-18

2.4-4 Component Minimum Workmanship Random Vibration Test Levels ..............................2.4-19

2.5-1 EMC Requirements per Level of Assembly .......................................................................2.5-2

2.5-2 Frequency Range and Modulation Associated With Orbiter Transmitters ......................2.5-11

2.6-1 Vacuum, Thermal, and Humidity Requirements ................................................................2.6-2

A-1 Acoustic Fill-Factor, 3 meter Payload Fairing .......................................................................A-2

FIGURES

Figure

2.1-1 Environmental Test Matrix .................................................................................................2.1-5

2.1-2a Verification Test Report......................................................................................................2.1-6

2.1-2b Verification Test Report (continued) ..................................................................................2.1-7

2.4-1 Shock Response Level (SRS) for Assessing Component Test Requirements ............2.4-26

2.5-1 Narrowband Conducted Emission Limits on Payload Power Leads................................2.5-15

2.5-1a Common Mode Conducted Emission Limits on Primary Power Lines ............................2.5-15

2.5-2 Broadband Conducted Emission Limits on Payload Power Leads..................................2.5-16

2.5-3 Limit Envelope of Cargo-Generated Transients (Line to Line) on DC Power Busses

for Normal Electrical System............................................................................................2.5-16

2.5-4 Orbiter DC Power Line Impedance ..................................................................................2.5-17


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2.5-5 Network Schematic for Simulating Impedance of Orbiter Power System........................2.5-17

2.5-6 Limits of Payload-Produced Spikes on Orbiter AC Power Leads....................................2.5-18

2.5-7 Deleted

2.5-8 Limits of Radiated AC Magnetic Field at 1 Meter from Orbiter Payload ..........................2.5-18

2.5-9 Unintentional Radiated Narrowband Limits for Electric Field Emission Produced by

Payloads and Payload Subsystems.................................................................................2.5-19

2.5-9a Allowable Unintentional Radiated Narrowband Emissions Limits in Orbiter

Cargo Bay ........................................................................................................................2.5-19

2.5-10 Unintentional Radiated Broadband Limits for Electric Field Emissions Produced by

Payloads and Payload Subsystems.................................................................................2.5-20

2.5-11 Allowable Intentional Field Strength in Orbiter Cargo Bay...............................................2.5-20

2.5-12a Transient Voltage on the AFT Payload B and C DC Buses Produced by Operation

of the Hydraulic Circulation Pump....................................................................................2.5-21

2.5-12b Transient Voltage on the Primary Payload Bus, Auxiliary Payload A, Auxiliary

Payload B, and the Cabin Payload Bus at the Cargo Element Interface Produced

by Operation of the Hydraulic Circulation Pump..............................................................2.5-21

2.5-13 Envelope of Spikes on the Orbiter AC Power Bus...........................................................2.5-22

2.5-14a Maximum Field Intensities on Payload Envelope Produced by Orbiter Transmitters......2.5-22

2.5-14b S-Band FM Transmitter, Upper HEMI Antenna, Maximum Field Intensities ...................2.5-23

2.5-14c S-Band Payload Interrogator, Maximum Field Intensities................................................2.5-24

2.5-14d S-Band Network Transponder, Upper Quad Antennas, Maximum Field Intensities .......2.5-25

2.5-14e S-Band Network Transponder, Upper Quad Antennas, Beam Configuration .................2.5-26

2.5-15 Orbiter-Produced Radiated Narrowband Emissions in Payload Bay...............................2.5-27

2.5-16 Orbiter-Produced Radiated Broadband Emissions in Payload Bay.................................2.5-27

2.6-1 Section 2.6 Thermal Requirements ...................................................................................2.6-3

2.6-2 Qualification (Protoflight or Prototype) and Flight Acceptance Thermal-Vacuum

Temperatures.....................................................................................................................2.6-5

2.6-3 Temperature-Humidity Profile for Descent and Landing Demonstration.........................2.6-12


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A-1 Cylindrical Payload in Fairing Acoustic Fill-Factor................................................................A-1

A-2 Acoustic Fill-Factor for Various Size Payloads in a 3 Meter Diameter Payload Fairing.......A-3

A-3 Determination of Qualification and Acceptance Random Vibration Test Levels ..................A-4

A-4 Shock Environment Produced by Linear Pyrotechnic Devices.............................................A-7

A-5 Shock Environment Produced by Separation Nuts and Explosive Bolts ..............................A-8

A-6 Shock Environment Produced by Pin-Pullers and Pin-Pushers ...........................................A-9

A-7 Shock Environment Produced by Bolt-Cutters, Pin-Cutters, and Cable-Cutters............... A-10

A-8 Attenuation of Constant Velocity Line ................................................................................ A-11

A-9 Peak Pyrotechnic Shock Response vs Distance ............................................................... A-12

A-10 Shock Attenuation Example............................................................................................... A-13

A-11 Reduction of Pyrotechnic Shock Response due to Intervening Structure......................... A-14


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SECTION l

GENERAL INFORMATION


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GENERAL INFORMATION ________________________________________GENERAL INFORMATION

1-1

1.1 PURPOSE

This standard provides requirements and guidelines for environmental verification programs

for GSFC payloads, subsystems and components and describes methods for implementing

those requirements. It contains a baseline for demonstrating by test or analysis the

satisfactory performance of hardware in the expected mission environments, and thatminimum workmanship standards have been met. It elaborates on those requirements,

gives guideline test levels, provides guidance in the choice of test options, and describes

acceptable test and analytical methods for implementing the requirements.

This standard shall be used by GSFC projects and contractors. This standard shall be

tailored to create a project specific verification plan and verification specification as

discussed in section 2.1. GSFC projects must select from the options to fulfill the specific

payload (spacecraft) requirements in accordance with the launch vehicle to be used, Space

Transportation System (STS), Atlas, Delta, Pegasus, Titan, etc., or to cover other mission-

specific considerations. Most of the verification program is generally the same for STS and

the expendable launch vehicles (ELV) payloads (spacecraft); the differences are noted in

the text and the tables.

1.2 APPLICABILITY AND LIMITATIONS

This standard applies to GSFC hardware and associated software that is to be launched on

either the STS or on an ELV. Hardware launched by balloons and sounding rockets is not

included. The specification applies to the following:

a. All space flight hardware, including interface hardware, that is developed as part of a

payload managed by GSFC, whether developed by (1) GSFC or any of its

contractors, (2) another NASA center, or (3) an independent agency; and

b. All space flight hardware, including interface hardware that is developed by GSFC or

any of its contractors and that is provided to another NASA installation or independent

agency as part of a payload that is not managed by GSFC.

The provisions herein are generally limited to the verification of STS or ELV payloads and to

those activities (with emphasis on the environmental verification program) that are closely

associated with such verification, such as workmanship and functional testing. If the

payload is to be serviced or recovered by the STS, then all STS verification and safety

requirements apply.

The standard is written in accordance with the current GSFC practice of using a single

protoflight payload for both qualification testing and space flight (see definition of hardware,1.8). The protoflight verification program, therefore, is given as the nominal test program.

1.3 THE GSFC VERIFICATION APPROACH

Goddard Space Flight Center endorses the full systems verification approach in which the

entire payload is tested or verified under conditions that simulate the flight operations and

flight environment as realistically as possible. The standard is written in accordance with

that view. However, it is recognized that there may be unavoidable exceptions, or conditions


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1-2

which make it preferable to perform the verification activities at lower levels of assembly.

For example, testing at lower levels of assembly may be necessary to produce sufficient

environmentally induced stresses to uncover design and workmanship flaws. These test

requirements should be tailored for each specific space program. For some projects,

tailoring might relax the requirements in this standard; however, for other projects the

requirements may be made more stringent to demonstrate more robustness or greater

confidence in the system performance.

Since testing at the component (or unit) level, or lower level of assembly for large

components, often becomes a primary part of the verification program, all components

should be operating and monitored during all environmental tests if practicable.

Environmental verification of hardware is only a portion of the total assurance effort at GSFC

that establishes confidence that a payload will function correctly and fly a successful

mission. The environmental test program provides confidence that the design will perform

when subjected to environments more severe than expected during the mission, and

provides environmental stress screening to uncover workmanship defects.

The total verification process also includes the development of models representing the

hardware, tests to verify the adequacy of the models, analyses, alignments, calibrations,functional/performance tests to verify proper operation, and finally end-to-end tests and

simulations to show that the total system will perform as specified.

Other tests not included herein may be performed as required by the project. The level,

procedure, and decision criteria for performing any such additional tests shall be included in

the system verification plan and system verification specification (section 2.1).

1.4 OTHER ASSURANCE REQUIREMENTS

In addition to the verification program, the assurance effort include parts and materials

selection and control, reliability assessment, quality assurance, software assurance, design

reviews, and system safety.

1.5 RESPONSIBILITY FOR ADMINISTRATION

The responsibility and authority for decisions in applying the requirements of this standard

rest with the project manager. The general/environmental requirements are intended for use

by the flight project managers, assisted by the systems assurance managers, and systems

engineering in developing project-unique performance verification requirements, plans, and

specifications that are consistent with current NASA program/project planning.

The requirements thus derived and deviations from the requirements of this document are

subject to review and approval by the GSFC Office of Mission Success.

1.6 GEVS CONFIGURATION CONTROL AND DISTRIBUTION

This document is controlled and maintained by the GSFC Office of Mission Success, and is

available through the Goddard Document Management System (GDMS).


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1-3

1.7 APPLICABLE DOCUMENTS

The following documents may be needed in formulating the environmental test program.

The user must ensure that the latest versions are procured and that the most recent

changes and additions are included.

1.7.1 Safety Requirements - NSTS 1700.7, Safety Policy and Requirements for Payloads usingthe NSTS, states that "the safety of any hazardous payload safety-critical equipment shall

be satisfactorily verified." Because testing is one of the acceptable methods for verifying

safety compliance, the environmental test program may be influenced by safety

considerations.

1.7.2 NSTS Interface Requirements - Portions of ICD 2-19001, Shuttle Orbiter/Cargo Standard

Interfaces (Attachment 1 to NSTS 07700, Vol. XIV) have been incorporated herein primarily

to make up part of the electromagnetic compatibility (EMC) provisions. ICD 2-19001 should

also be consulted as indicated for implementing some of the other sections. Similarly, many

of the provisions of NSTS 14046, Payload Interface Verification Requirements have been

incorporated in this specification. STS users should, however, refer to that document to

ensure full compliance.

1.7.3 ELV Payload User Manuals - The most recent version of the launch vehicle user manual

and requirements are applicable in accordance with the launch vehicle to be used by the

project and should be acquired from the service provider.

1.7.4 Fracture Control and Stress Corrosion - NSTS 1700.7, above, states the policy on fracture

control for the STS. MSFC-STD-3029, provides guidelines for the selection of metallic

materials. NASA-STD-5003 Fracture Control Requirements for Payloads using the Space

Shuttle (1.7.7.h), and MSFC-STD-1249, Standard NDE Guidelines and Requirements for

Fracture Control Programs (1.7.9.c) provide additional requirements.

1.7.5 Spacecraft Tracking and Data Network Simulation - STDN No. 101.6, Portable Simulation

System and Simulations Operation Center Guide for TDRSS & GSTDN, describes the

Spacecraft Tracking and Data Network (STDN) and the Tracking and Data Relay Satellite(TDRS)/Ground STDN network simulation programs, and the Simulations Operations Center

(SOC). It also discusses end-to-end simulation techniques. STDN No. 408, TDRS and

GSTDN Compatibility Test Van Functional Description and Capabilities, describes the

equipment and the compatibility test system.

1.7.6 Deep Space Network (DSN) Simulation - The Deep Space Network/Flight Project Interface

Design Handbook, 8l0-5, Jet Propulsion Laboratory, California Institute of Technology, Vol. I,

Module TSS-10, describes existing payload (spacecraft) telemetry and command simulation

capability. Vol. II describes proposed DSN capability.

1.7.7 NASA Standards The following standards provide supporting information:

a. NASA-STD 7002, Payload Test Requirements

b. NASA-STD-7001, Payload Vibroacoustic Test Criteria

c. NASA-STD-7003, Pyroshock Test Criteria

d. NASA-HDBK-7004, Force Limited Vibration Testing

e. NASA-HDBK-7005, Dynamic Environmental Criteria


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f. NASA-STD-5001, Structural Design and Test Factors of Safety for Space Flight

Hardware

g. NASA-STD-5002, Load Analyses of Spacecraft and Payloads

h. NASA-STD-5003, Fracture Control Requirements for Payloads using the SpaceShuttle

i. NASA-STD-5007, General Fracture Control Requirements for Manned Spaceflight

Systems

l.7.8 Military Standards for EMC Testing - Pertinent sections of the following standards are

needed to conduct the EMC tests:

a. MIL-STD-461C, Electromagnetic Interference Characteristics Requirements for

Equipment.

b. MIL-STD-462, Electromagnetic Interference Characteristics, Measurement of, as

amended by Notice l.

c. MIL-STD-463A, Definitions and Systems of Units, Electromagnetic Interference and

Electromagnetic Compatibility Technology.

1.7.9 Military Standards for Non-Destructive Evaluation

a. MIL-HDBK-6870, Inspection Program Requirements, Non-Destructive Testing for

Aircraft and Missile Materials and Parts.

b. NAS-410, Certification and Qualification of Nondestructive Test Personnel.

c. MSFC-STD-1249, Standard NDE Guidelines and Requirements for Fracture ControlPrograms.

d. MIL-HDBK-728, Nondestructive Testing.

1.8 DEFINITIONS

The following definitions apply within the context of this specification:

Acceptance Tests: The verification process that demonstrates that hardware is acceptable

for flight. It also serves as a quality control screen to detect deficiencies and, normally, to

provide the basis for delivery of an item under terms of a contract.

Assembly: See Level of Assembly.

Component: See Level of Assembly.

Configuration: The functional and physical characteristics of the payload and all its integral

parts, assemblies and systems that are capable of fulfilling the fit, form and functional

requirements defined by performance specifications and engineering drawings.


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Contamination: The presence of materials of molecular or particulate nature which degrade

the performance of hardware.

Design Qualification Tests: Tests intended to demonstrate that the test item will function

within performance specifications under simulated conditions more severe than those

expected from ground handling, launch, and orbital operations. Their purpose is to uncover

deficiencies in design and method of manufacture. They are not intended to exceed designsafety margins or to introduce unrealistic modes of failure. The design qualification tests

may be to either prototype or protoflight test levels.

Design Specification: Generic designation for a specification that describes functional and

physical requirements for an article, usually at the component level or higher levels of

assembly. In its initial form, the design specification is a statement of functional

requirements with only general coverage of physical and test requirements. The design

specification evolves through the project life cycle to reflect progressive refinements in

performance, design, configuration, and test requirements. In many projects the end-item

specifications serve all the purposes of design specifications for the contract end-items.

Design specifications provide the basis for technical and engineering management control.

Electromagnetic Compatibility (EMC): The condition that prevails when various electronicdevices are performing their functions according to design in a common electromagnetic

environment.

Electromagnetic Interference (EMI): Electromagnetic energy which interrupts, obstructs, or

otherwise degrades or limits the effective performance of electrical equipment.

Electromagnetic Susceptibility: Undesired response by a component, subsystem, or system

to conducted or radiated electromagnetic emissions.

End-to-End Tests: Tests performed on the integrated ground and flight system, including all

elements of the payload, its control, stimulation, communications, and data processing to

demonstrate that the entire system is operating in a manner to fulfill all mission requirements

and objectives.

Failure: A departure from specification that is discovered in the functioning or operation of

the hardware or software. See nonconformance.

Flight Acceptance: See Acceptance Tests.

Fracture Control Program: A systematic project activity to ensure that a payload intended

for flight has sufficient structural integrity as to present no critical or catastrophic hazard.

Also to ensure quality of performance in the structural area for any payload (spacecraft)

project. Central to the program is fracture control analysis, which includes the concepts of

fail-safe and safe-life, defined as follows:

a. Fail-safe: Ensures that a structural element, because of structural redundancy, will

not cause collapse of the remaining structure or have any detrimental effects on

mission performance.

b. Safe-life: Ensures that the largest flaw that could remain undetected after non-

destructive examination would not grow to failure during the mission.

Functional Tests: The operation of a unit in accordance with a defined operational

procedure to determine whether performance is within the specified requirements.


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Hardware: As used in this document, there are two major categories of hardware as follows:

a. Prototype Hardware: Hardware of a new design; it is subject to a design qualification

test program; it is not intended for flight.

b. Flight Hardware: Hardware to be used operationally in space. It includes the followingsubsets:

(1) Protoflight Hardware: Flight hardware of a new design; it is subject to a

qualification test program that combines elements of prototype and flight

acceptance verification; that is, the application of design qualification test levels

and flight acceptance test durations.

(2) Follow-On Hardware: Flight hardware built in accordance with a design that

has been qualified either as prototype or as protoflight hardware; follow-on

hardware is subject to a flight acceptance test program.

(3) Spare Hardware: Hardware the design of which has been proven in a design

qualification test program; it is subject to a flight acceptance test program andis used to replace flight hardware that is no longer acceptable for flight.

(4) Reflight Hardware: Flight hardware that has been used operationally in space

and is to be reused in the same way; the verification program to which it is

subject depends on its past performance, current status, and the upcoming

mission.

Level of Assembly: The environmental test requirements of GEVS generally start at the

component or unit level assembly and continue hardware/software build through the system

level (referred to in GEVS as the payload or spacecraft level). The assurance program

includes the part level. Verification testing may also include testing at the assembly and

subassembly levels of assembly; for test record keeping these levels are combined into a

"subassembly" level. The verification program continues through launch, and on-orbitperformance. The following levels of assembly are used for describing test and analysis

configurations:

Assembly: A functional subdivision of a component consisting of parts or

subassemblies that perform functions necessary for the operation of the component

as a whole. Examples are a power amplifier and gyroscope.

Component: A functional subdivision of a subsystem and generally a self-contained

combination of items performing a function necessary for the subsystem's operation.

Examples are electronic box, transmitter, gyro package, actuator, motor, battery. For

the purposes of this document, "component" and "unit" are used interchangeably.

Instrument: A spacecraft subsystem consisting of sensors and associated hardware

for making measurements or observations in space. For the purposes of this

document, an instrument is considered a subsystem (of the spacecraft).

Module: A major subdivision of the payload that is viewed as a physical and

functional entity for the purposes of analysis, manufacturing, testing, and

recordkeeping. Examples include spacecraft bus, science payload, and upper stage

vehicle.


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Part: A hardware element that is not normally subject to further subdivision or

disassembly without destruction of design use. Examples include resistor, integrated

circuit, relay, connector, bolt, and gaskets.

Payload: An integrated assemblage of modules, subsystems, etc., designed to

perform a specified mission in space. For the purposes of this document, "payload"

and "spacecraft" are used interchangeably. Other terms used to designate this level ofassembly are Laboratory, Observatory, Satellite and System Segment.

Spacecraft: See Payload. Other terms used to designate this level of assembly are

Laboratory, Observatory, and satellite.

Section: A structurally integrated set of components and integrating hardware that

form a subdivision of a subsystem, module, etc. A section forms a testable level of

assembly, such as components/units mounted into a structural mounting tray or

panel-like assembly, or components that are stacked.

Subassembly: A subdivision of an assembly. Examples are wire harness and loaded

printed circuit boards.

Subsystem: A functional subdivision of a payload consisting of two or more

components. Examples are structural, attitude control, electrical power, and

communication subsystems. Also included as subsystems of the payload are the

science instruments or experiments.

Unit: A functional subdivision of a subsystem, or instrument, and generally a self-

contained combination of items performing a function necessary for the subsystem's

operation. Examples are electronic box, transmitter, gyro package, actuator, motor,

battery. For the purposes of this document, "component" and "unit" are used

interchangeably.

Limit Level: The maximum expected flight level (consistent with the minimum probabilitylevels of Table 2.4-2).

Margin: The amount by which hardware capability exceeds requirements.

Module: See Level of Assembly.

Nonconformance: A condition of any hardware, software, material, or service in which one

or more characteristics do not conform to specified requirements.

Offgassing: The emanation of volatile matter of any kind from materials into a manned

pressurized volume.

Outgassing: The emanation of volatile materials under vacuum conditions resulting in a

mass loss and/or material condensation on nearby surfaces.

Part: See Level of Assembly.

Payload: See Level of Assembly.

Performance Verification: Determination by test, analysis, or a combination of the two that

the payload element can operate as intended in a particular mission; this includes being


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satisfied that the design of the payload or element has been qualified and that the particular

item has been accepted as true to the design and ready for flight operations.

Protoflight Testing: See Hardware.

Prototype Testing: See Hardware.

Qualification: See Design Qualification Tests.

Redundancy (of design): The use of more than one independent means of accomplishing a

given function.

Section: See Level of Assembly.

Spacecraft: See Level of Assembly.

Subassembly: See Level of Assembly.

Subsystem: See Level of Assembly.

Temperature Cycle: A transition from some initial temperature condition to temperature

stabilization at one extreme and then to temperature stabilization at the opposite extreme

and returning to the initial temperature condition.

Temperature Stabilization: The condition that exists when the rate of change of

temperatures has decreased to the point where the test item may be expected to remain

within the specified test tolerance for the necessary duration or where further change is

considered acceptable.

Thermal Balance Test: A test conducted to verify the adequacy of the thermal model, the

adequacy of the thermal design, and the capability of the thermal control system to maintain

thermal conditions within established mission limits.

Thermal-Vacuum Test: A test conducted to demonstrate the capability of the test item to

operate satisfactorily in vacuum at temperatures based on those expected for the mission.

The test, including the gradient shifts induced by cycling between temperature extremes,

can also uncover latent defects in design, parts, and workmanship.

Unit: See Level of Assembly.

Vibroacoustics: An environment induced by high-intensity acoustic noise associated with

various segments of the flight profile; it manifests itself throughout the payload in the form of

directly transmitted acoustic excitation and as structure-borne random vibration.

Workmanship Tests: Tests performed during the environmental verification program toverify adequate workmanship in the construction of a test item. It is often necessary to

impose stressses beyond those predicted for the mission in order to uncover defects. Thus

random vibration tests are conducted specifically to detect bad solder joints, loose or

missing fasteners, improperly mounted parts, etc. Cycling between temperature extremes

during thermal-vacuum testing and the presence of electromagnetic interference during

EMC testing can also reveal the lack of proper construction and adequate workmanship.


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1-9

1.9 CRITERIA FOR UNSATISFACTORY PERFORMANCE

Deterioration or any change in performance of any test item that does or could in any

manner prevent the item from meeting its functional, operational, or design requirements

throughout its mission shall be reason to consider the test item as having failed. Other

factors concerning failure are considered in the following paragraphs.

1.9.1 Failure Occurrence

When a failure (non-conformance or trend indicating that an out of spec condition will result)

occurs, a determination shall be made as to the feasibility and value of continuing the test to

its specified conclusion. If corrective action is taken, the test shall be repeated to the extent

necessary to demonstrate that the test item's performance is satisfactory.

1.9.2 Failures with Retroactive Effects

If corrective action taken as a result of failure, e.g. redesign of a component, affects the

validity of previously completed tests, prior tests shall be repeated to the extent necessary to

demonstrate satisfactory performance.

1.9.3 Failure Reporting

Every failure shall be recorded and reported in accordance with the failure reporting

provisions of the project.

1.9.4 Wear Out

If during a test sequence a test item is operated in excess of design life and wears out or

becomes unsuitable for further testing from causes other than deficiencies, a spare may be

substituted. If, however, the substitution affects the significance of test results, the test

during which the item was replaced and any previously completed tests that are affected

shall be repeated to the extent necessary to demonstrate satisfactory performance.

1.10 TEST SAFETY RESPONSIBILITIES

The following paragraphs define the responsibilities shared by the space project and facility

management for planning and enforcing industrial safety measures taken during testing for

the protection of personnel, the payload, and the test facility.

1.10.1 Operations Hazard Analysis, Responsibilities For

It shall be the joint responsibility of the test facility manager and the project manager to

ensure that environmental tests and associated operations present no unacceptable hazard

to the test item, facilities, or personnel. A test operations hazard analysis (OHA) shall be

performed by the facility and project personnel to consider and evaluate all hazardspresented by the interaction of the payload and the facility for each environmental test. All

hazards discovered in the OHA shall be tracked to an agreed-upon resolution. The safety

measures to be taken as a result of the OHA, as well as the safety measures between tests,

shall be specified as requirements in the verification plan and verification specification. (sec.

2.1.1)


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1.10.2 Treatment of Hazards

As hazards are discovered, a considered attempt shall be made to eliminate them. This

may be accomplished by redesign, controlling energy sources, revising the test, or by some

other method. If the hazard cannot be eliminated, automatic safety controls shall be applied,

for example: pressure relief devices, electrical circuit protection devices, or mechanical

interlocks. If that is not possible or is too costly, warning devices shall be considered. Ifnone of the foregoing methods are practicable, control procedures must be developed and

applied. In practice, a combination of all four methods may be the best solution to the

hazards posed by a complex system. Before any test begins, the project manager and test

facility management shall agree on the hazard control method(s) that are to be used.

1.10.3 Facility Safety

The test facility manager shall verify that the test facility and normal operations present no

unacceptable hazard to the test item, test and support equipment, or personnel. He shall

ensure that facility personnel abide by all applicable regulations, observe all appropriate

industrial safety measures, and follow all requirements for protective equipment. He shall

ensure that all facility personnel are trained and qualified for their positions. Training shouldinclude the handling of emergencies by the simulation of emergency conditions. Analyses,

tests, and inspections shall be performed to verify that the safety requirements are satisfied.

The approach outlined in 1.11.2 shall be used to eliminate or control hazards.

1.10.4 Safety Responsibilities During Tests

The test facility manager shall appoint a safety officer to work closely with a safety officer

designated by the space project. The facility designee shall ensure that the facility meets

applicable Occupational Safety & Health Act (OSHA) and other requirements, that

appropriate industrial safety measures are observed, and that protective equipment is

provided for all personnel involved. The facility designee will ensure that facility personnel

use the equipment provided and that the test operation does not present a hazard to thefacility. The project designee shall ensure that project personnel use the equipment

provided and that the test operation does not present a hazard to the space hardware,

equipment, or personnel.

1.11 TESTING OF SPARE HARDWARE

A supply of selected spares is often maintained in case of the failure of flight hardware. As a

minimum, spares must undergo a verification program equal to that required for follow-on

hardware. Therefore, special consideration must be given to spares as follows:

a. Extent of Testing - The extent and type of testing shall be determined as part of theflight hardware test program. A spare unit may be used for qualification of the

hardware by subjecting it to protoflight testing, and testing the flight hardware to

acceptance levels.

b. Spares From Failed Elements - If a flight element is replaced for reasons of failure

and is then repaired and redesignated as a spare, appropriate retesting shall be

conducted.


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c. Caution on the Use of Spares - When the need for a spare arises, immediate

analysis and review of the failed hardware must be made. If failure occurs in a

hardware item of which there are others of identical design, the fault may be generic

and may affect all hardware of that design.

d. "One-Shot" Items - Some items may be degraded or expended during the integration

and test period and replaced by spares. The spare that is used shall have met therequired quality control standards or auxiliary tests for such items and shall be of

qualified design. Examples are pyrotechnic devices, yo-yo despin weights, and

elements that absorb impact energy by plastic yielding. When the replacement entails

procedures that could jeopardize mission success, the replacement procedure should

be successfully demonstrated with the hardware in the same configuration that it will

be in when final replacement is to be accomplished.

1.12 TEST FACILITIES, CALIBRATION

The facilities and fixtures used in conducting tests shall be capable of producing and

maintaining the test conditions prescribed with the test specimen installed and operating or

not operating, as required. In any major test, facility performance should be verified prior tothe test either by a review of its performance during a test that occurred a short time earlier

or by conducting a test with a substitute test item. All equipment used for tests shall be in

current calibration and so noted by tags and stickers.

1.13 TEST CONDITION TOLERANCES

In the absence of a rationale for other test condition tolerances, the following shall be used;

the values include measurement uncertainties:

Acoustics Overall Level:

1 dB

l/3 Octave Band Tolerance: Frequency (Hz) Tolerance (dB)

f 40 +3, -6

40< F < 3150 3

f 3150 +3, -6

Antenna Pattern Determination 2 dB

Electromagnetic Compatibility

Voltage Magnitude: 5% of the peak value

Current Magnitude: 5% of the peak value

RF Amplitudes: 2 dB

Frequency: 2%

Distance: 5% of specified distance or

5 cm, whichever is greater


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Humidity 5% RH

Loads Steady-State (Acceleration): 5%

Static: 5%

Magnetic Properties

Mapping Distance Measurement: 1 cm

Displacement of assembly center of gravity (cg)

from rotation axis: 5 cm

Vertical displacement of single probe centerline

from cg of assembly: 5 cm

Mapping turntable angular displacement: 3 degrees

Magnetic Field Strength: 1 nT

Repeatability of magnetic measurements (short term): 5% or 2 nT,

whichever is greater

Demagnetizing and Magnetizing Field Level: 5% of nominal

Mass Properties Weight: 0.2%

Center of Gravity: 0.15cm ( 0.06 in.)

Moments of Inertia: 1.5%

Mechanical Shock Response Spectrum: +25%, -10%

Time History: 10%

Pressure Greater than 1.3 X 104 Pa

(Greater than 100 mm Hg): 5%

1.3 X l04 to 1.3 X l02 Pa

(l00 mm Hg to 1 mm Hg): 10%

1.3 X l02 to 1.3 X 101 Pa

(1 mm Hg to 1 micron):

25%

Less than 1.3 X 101 Pa

(less than 1 micron): 80%

Temperature 2C


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Vibration Sinusoidal: Amplitude 10%

Frequency 2%

Random: RMS level 10%

Accel. Spectral Density 3 dB


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SECTION 2

VERIFICATION PROGRAM


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SECTION 2.1

SYSTEM PERFORMANCE VERIFICATION


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SYSTEM PERFORMANCE VERIFICATION SYSTEM PERFORMANCE VERIFICATION

2.1- 1

2.l SYSTEM PERFORMANCE VERIFICATION

This section applies to all payloads (spacecraft), subsystems (including

instruments), and components. The basic provisions apply to all flight hardware,

and associated software, that will fly in the STS cargo bay and to spacecraft that willbe launched by expendable launch vehicles (ELVs).

The GEVS, as its name implies, provides basic requirements and guidelines for an

environmental verification program. This represents only a portion of the overall

system verification and must be integrated into the total system program which

verifies that the system will meet the mission requirements. A system performance

verification program documenting the overall verification plan, implementation, and

results is required which will provide traceability from mission specification

requirements to launch and initial on-orbit capability. This will also provide the

baseline for tracking on-orbit performance versus pre-launch capability.

2.1.1 Documentation Requirements

The following documents are required and shall be delivered and approved in

accordance with the Contracts Schedule.

2.1.1.1 System Performance Verification Plan

A system performance verification plan shall be prepared defining the tasks and

methods required to determine the ability of the system (or instrument) to meet each

program-level performance requirement (structural, thermal, optical, electrical,

guidance/control, RF/telemetry, science, mission operational, etc.) and to measure

specification compliance. Limitations in the ability to verify any performance

requirement shall be addressed, including the addition of supplemental tests and/oranalyses that will be performed and a risk assessment of the inability to verify the

requirement.

The plan shall address how compliance with each specification requirement will be

verified. If verification relies on the results of measurements and/or analyses

performed at lower (or other) levels of assembly, this dependence shall be

described.

For each analysis activity, the plan shall include objectives, a description of the

mathematical model, assumptions on which the models will be based, required

output, criteria for assessing the acceptability of the results, the interaction with

related test activity, if any, and requirements for reports. Analysis results shall takeinto account tolerance build-ups in the parameters being used.

2.1.1.1.1 Environmental Verification Plan

An environmental verification plan shall be prepared, either as part of the System

Verification Plan or as a separate document, that prescribes the tests and analyses

that will collectively demonstrate that the hardware and software comply with the

environmental verification requirements


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2.1- 2

The environmental verification plan shall provide the overall approach to

accomplishing the environmental verification program. For each test, it shall include

the level of assembly, the configuration of the item, objectives, facilities,

instrumentation, safety considerations, contamination control, test phases and

profiles, necessary functional operations, personnel responsibilities, and

requirement for procedures and reports. It shall also define a rationale for retestdetermination that does not invalidate previous verification activities. When

appropriate, the interaction of the test and analysis activity shall be described.

Limitations in the environmental verification program which preclude the verification

by test of any system requirement shall be documented. Examples of limitations in

the ability to demonstrate requirements include:

Inability to deploy hardware in a 1-g environment.

Facility limitations which do not allow testing at system level of assembly.

Inability to perform certain tests because of contamination control

requirements.

Inability to perform powered-on testing because of voltage breakdown

concerns.

Alternative tests and analyses shall be evaluated and implemented as appropriate,

and an assessment of program risk shall be included in the System Performance

Verification Plan.

2.1.1.2 System Performance Verification Matrix

A System Performance Verification Matrix shall be prepared, and maintained, to

show each specification requirement, the reference source (to the specificparagraph or line item), the method of compliance, applicable procedure references,

results, report reference numbers, etc. This matrix shall be included in the system

review data packages showing the current verification status as applicable

2.1.1.2.1 Environmental Test Matrix

As an adjunct to the environmental verification plan, an environmental test matrix

shall be prepared that summarizes all tests that will be performed on each

component, each subsystem, and the payload. The purpose is to provide a ready

reference to the contents of the test program in order to prevent the deletion of a

portion thereof without an alternative means of accomplishing the objectives; it has

the additional purpose of ensuring that all flight hardware has been subjected toenvironmental exposures that are sufficient to demonstrate acceptable

workmanship. In addition, the matrix shall provide traceability of the qualification

heritage of hardware. All flight hardware, spares and prototypes (when appropriate)

shall be included in the matrix. Details of each test shall be provided (e.g., number

of thermal cycles, temperature extremes, vibration levels). It shall also relate the

design environments to the test environments and to the anticipated mission

environments. The matrix shall be prepared in conjunction with the initial

environmental verification plan and shall be updated as changes occur.


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2.1- 3

A sample test matrix is given in Figure 2.1-1. The electrical performance tests that

are required to be performed before, during, and following the environmental

verification test program are not shown in this sample matrix. Other performance

tests, measurements, demonstrations, alignments, etc. (electrical, mechanical,

optical, etc.), that must be performed to verify hardware/software requirements are

also not included in this Environmental Test Matrix. However they shall be included

in the System Performance Verification Plan.

The test matrix does not have to conform to this format; any format that clearly

displays the pertinent information is acceptable.

A complementary matrix shall be kept showing the tests that have been performed

on each component, subsystem, or payload (or applicable level of assembly). This

should include tests performed on prototypes or engineering units used in the

qualification program, and should indicate test results (pass/fail or malfunctions).

2.1.1.3 Environmental Verification Specification

An environmental verification specification shall be prepared that defines the specificenvironmental parameters that each hardware element is subjected to either by test

or analysis in order to demonstrate its ability to meet the mission performance

requirements. Such things as payload peculiarities and interaction with the launch

vehicle (STS or ELV) shall be taken into account.

2.1.1.4 Performance Verification Procedures

For each verification test activity conducted at the component, subsystem, and

payload levels (or other appropriate levels) of assembly, a verification procedure

shall be prepared that describes the configuration of the test article, how each test

activity contained in the verification plan and specification will be implemented.

Test procedures shall contain details such as instrumentation monitoring, facility

control sequences, test article functions, test parameters, pass/fail criteria, quality

control checkpoints, data collection and reporting requirements. The procedures

also shall address safety and contamination control provisions.

2.1.1.5 Verification Reports

After each component, subsystem, payload, etc., verification activity has been

completed, a report shall be submitted in accordance with the Contract Schedule.

For each environmental test activity, the report shall contain, as a minimum, the

information in the sample test report contained in Figure 2.1-2a and 2.1-2b. Foreach analysis activity, the report shall describe the degree to which the objectives

were accomplished, how well the mathematical model was validated by related test

data, and other such significant results. In addition, as-run verification procedures

and all test and analysis data shall be retained for review.


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2.1- 4

2.1.1.6 System Performance Verification Report

At the conclusion of the verification program, a final System Performance

Verification Report shall be delivered comparing the hardware/software

specifications with the final verified values (whether measured or computed). It is

recommended that this report be subdivided by subsytem/instrument.

The System Performance Verification Report shall be maintained "real-time"

throughout the program summarizing the successful completion of verification

activities, and showing that the applicable system performance specifications have

been acceptably complied with prior to integration of hardware/software into the next

higher level of assembly.

The initial report shall be provided for the PDR. Current versions shall then be

provided for review at major systems reviews.

The final pre-launch System Verification Report shall be available for approval for

the FRR (Flight Readiness Review).

Following initial on-orbit checkout, the System Verification Report shall becompleted, and delivered in accordance with the contract schedule.

2.1.1.7 Instrument Verification Documentation

The documentation requirements of sections 2.1.1.1 through 2.1.1.6 also apply to

instruments. Following integration of the instruments onto the spacecraft, the

spacecraft System Verification Report will include the instrument information.


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2.1- 5


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2.1- 6

Figure 2.1-2a Verification Test Report


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2.1- 7

VERIFICATION TEST REPORT (Continued) Page_____of_____

Date (add time

for thermal and

temperature tests)

Note beginning and end of actual activity,

deviations from the planned procedure, and

discrepancies in test times or performance.

(State if there were no deviations or discrepancies.)

Malfunction Report

Number and Date

(if applicable)

(use additional paper as required)

The activities covered by these reports include tests and measurements performed for the purpose of verifying theflightworthiness of hardware at the component, subsystem, and payload levels of assembly. These reports shall also beprovided for such other activities as the project may designate.

These reports shall be completed and transmitted to the GSFC Technical Officer or Contracting Officer (as appropriate)within 30 days after completion of an activity. Legible, reproducible, handwritten completed forms are acceptable.

Material felt necessary to clarify this report may be attached. However, in general, test logs and data should be retainedby those responsible for the test item unless they are specifically requested.

The forms shall be signed by the quality assurance representative and the person responsible for the test or hisdesignated representative; the signatures represent concurrence that the data is as accurate as possible given theconstraints of time imposed by quick-response reporting.

This report does not replace the need for maintaining complete logs, records, etc.; it is intended to document theimplementation of the verification program and to provide a minimum amount of information as to the performance of thetest item.

Figure 2.1-2b Verification Test Report (cont.)


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SECTION 2.2

ENVIRONMENTAL VERIFICATION


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ENVIRONMENTAL VERIFICATION ENVIRONMENTAL VERIFICATION

2.2- 1

2.2 APPLICABILITY

Sections 2.3 through 2.8 give the basic environmental verification program for verifyingpayloads, subsystems, and components as follows:

2.3 Electrical Function & Performance

2.4 Structural and Mechanical

2.5 EMC

2.6 Thermal

2.7 Contamination Control

2.8 End-to-End Testing (payloads/spacecraft)

The verification program applies to payloads that will fly in the STS cargo bay and to

spacecraft that will be launched by expendable launch vehicles (ELVs). Provisions that are

specific to STS or ELV payloads are noted in the text and tables. For the purposes of this

document, a spacecraft is considered a payload, and an instrument is considered to be asubsystem when determining the environmental verification requirements.

The basic provisions are written assuming protoflight hardware. They are, in general, also

applicable to prototype hardware. Acceptance requirements are also given for the flight

acceptance of previously qualified hardware. This applies to follow-on hardware (multiple

copies of the same item) developed for the program, or hardware (from another program)

qualified by similarity.

2.2.1 Test Sequence and Level of Assembly

The verification activities herein are grouped by discipline; they are not in a recommended

sequence of performance. No specific environmental test sequence is required, but the test

program should be arranged in a way to best disclose problems and failures associated with

the characteristics of the hardware and the mission objectives.

In cases where the magnetic properties of the hardware need to be controlled, the dc

magnetics testing should be performed after vibration testing. This provides an opportunity

to correct for any magnetization of the flight hardware caused by fields associated with the

vibration test equipment.

Table 2.2-1 provides a hierarchy of levels of assembly for the flight hardware, with

examples. These level designators are based on those used in the Space Systems

Engineering Database developed by The Aerospace Corporation for the Air Force, and

agreed to by NASA Headquarters, GSFC, and JPL.. The GEVS environmental test

requirements generally start at the unit level and end at the system segment level.However, screening and life-tests often occur at lower levels, and overall system verification

continues beyond the system segment level.

2.2.2 Verification Program Tailoring

The environmental test requirements are written assuming a low-risk program. The

environmental program should be tailored to reflect the hardware classification, mission

objectives, hardware characteristics such as physical size and complexity, and the level of

risk accepted by the project. For example, the "failure-free-performance" requirement may


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2.2- 2

be varied, with GSFC approval, from the baseline to reflect mission duration and risk

acceptance. This document also assumes that the payload/spacecraft is of modular design

and can be tested at the unit/component, subsystem/instrument, and system/spacecraft

levels of assembly. Often this is not the case. The project must develop a verification

program that satisfies the intent of the required verification program while taking into

consideration the specific characteristics of the mission and the hardware. For example:

A spacecraft subsystem, or instrument, may be a functional subdivision of the

spacecraft, but it may be distributed throughout the spacecraft rather than being a

physical entity. In this case, the environmental tests, and associated functional tests,

must be performed at physical levels of assembly (component, section, module,

system or instrument [refer to Appendix A - hardware level of assembly]) that are

appropriate for the specific hardware. Performance tests and calibrations may still be

performed on the functional subsystem or instrument.

The physical size of the system may necessitate testing at other levels of assembly.

Facility limitations may not allow certain environmental tests to be performed at the

system level. In this case, testing should be performed at the highest practicable

level. Also, for very large systems or subsystems/instruments, tests at additional

levels of assembly may be added in order to adequately verify the hardware design,workmanship and/or performance.

For small payloads, the subsystem level environmental tests may be skipped in favor

of testing at the component and system/spacecraft levels. Similarly, for very small

instruments the GSFC project may elect to not test all components in favor of testing

at the instrument level. These decisions must be made carefully, especially regarding

bypassing lower level testing for instruments, because of the increased risk to the

program (schedule, cost, etc.) of finding problems late in the planned schedule.

In some cases, because of the hardware configuration it may be reasonable to test

more than one component at a time. The components may be stacked in their flight

configuration, and may therefore be tested as a "section". Part of the decision

process must consider the physical size and mass of the hardware. The test

configuration must allow for adequate dynamic or thermal stress inputs to the

hardware to uncover design errors and workmanship flaws.

Some test requirements stated as subsystem/instrument requirements may be

satisfied at a higher level of assembly if approved by the GSFC project. For example,

externally induced mechanical shock test requirements may be satisfied at the system

level by firing the environment-producing pyro. A simulation of this environment is

difficult, especially for large subsystems or instruments.

Aspects of the design and/or mission may negate certain test conditions to be

imposed. For example, if the on-orbit temperature variations are small, less than 5C,

then consideration should be given to waiving the thermal-vacuum cycling at thesystem, or instrument, level of assembly in favor of increasing the hot and cold dwell

times.

The same process must be applied when developing the test plan for an instrument. While

testing is required at the instrument component and all-up instrument levels of assembly,

additional test levels may be called for because of hardware complexity or physical size.


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2.2- 3

Table 2.2-1

Flight System Hardware

Levels of Assembly

.

2.2.3 Qualification of Hardware by Similarity

There are cases in which hardware qualified for one flight program is to be built and used on

another program. Hardware that has been previously qualified may be considered qualifiedfor use on a new program by showing that the hardware is sufficiently similar to the originalhardware and that the previous qualification program has adequately enveloped the newmission environments. The details for performing this comparison should be defined by theproject but as a minimum the following areas should be reviewed and documented:

(1) Design and test requirements must be shown to envelope the original requirements.This should include a review of the test configuration and of all waivers and deviationsthat may have occurred during testing of the original hardware.


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2.2- 4

(2) Manufacturing information shall be reviewed to determine if changes have been madethat would invalidate the previous hardware qualification. This review should coverparts, materials, packaging techniques as well as changes to the assembly process orprocedures.

(3) Test experience with the previous flight build shall be reviewed to verify that nosignificant modifications were made to the hardware during testing to successfullycomplete the test program. Any significant change s

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